Combinatorial tests of heterogeneous catalysts are known from, amongst others, WO 99/41005. In that reference, a process is described for the parallel testing of multiple materials with respect to their catalytic properties. In a tubular bundle reactor, a multitude of active masses is reacted with identical mixtures of educt gases in spatially separated channels. The products contained in the exhaust flow of materials are then characterized analytically and quantified, e.g., by gas chromatography. Due to the compact design and the fact that the catalysts can be studied under realistic conditions, up to 100 types of materials can be tested sensibly. However, a larger-scale reactor of this type can hardly be realized due to its inert heating and cooling behavior and its high gas consumption. In addition, the time required for analysis would not be tolerable.
The reference WO 00/51720 describes microreactors of an array of catalysts and takes only the reaction step into account. The procedure as described in the reference is strongly adapted to the analysis of adsorbers and relies mostly on layers or films as far as the materials to be screened are concerned. Assembling and disassembling a new library is not straightforward, i.e. cumbersome and requiring manual work. Also, open libraries are used in most cases, limiting the scope for storage.
The technology of mass spectroscopy as described in WO 00/29844 is cumbersome to handle since all materials to be screened have to be present as pellets or the like. The design of the reactor basically requires that these pellets have to be exchanged perpetually. In addition, the design is not truly two-dimensional. Storage of the materials is not possible and the potential for automation is highly limited.
Microreactors for heterogeneously catalyzed reactions, as described in the literature, are almost exclusively limited to using microreators for manufacturing products. The concept of parallel coupling is mentioned only in WO 00/51720. In the case of microreactors, catalysts are mostly applied as catalytically active layers. The embedding of micro-packed bulk goods is described in the work of Jensen/MIT (M. W. Losey, M. A. Schmidt, K. F. Jensen: A micro-packed bed reactor for chemical synthesis, in: W. Ehrfeld (Ed.): Microreaction Technology: Industrial Prospects, Proceedings of the 3rd International Conference on Microreaction Technology, Springer, 2000, 277-286), albeit without taking parallel coupling into account.
A glass reactor is described in: J. Antes, T. Tuercke, E. Marioth, K. Schmid, H. Krause, S. Loebbecke: Use of microreactors for nitration processes, 4th International Conference on Microreaction Technology, Topical Conference Proceedings, Atlanta/Ga., March 2000, 194-200. Here, product analysis is performed using IR transmission. This technique can also be applied for screening. Furthermore, the following studies are known with respect to combining microreactors and IR analysis: T. M. Floyd, K. F. Jensen, M. A. Schmidt: Towards integration of chemical detection for liquid phase microchannel reactors, 4th International Conference on Microreaction Technology, Topical Conference Proceedings, Atlanta/Ga., March 2000, 461-466 as well as A. E. Guber, W. Bier, K. Schubert: IR spectroscopic studies of a chemical reaction in various micromixer designs, 2nd International Conference on Microreaction Technology, Topical Conference Preprints, New Orleans/La., March 1998, 284-289. However, these studies describe the evaluation of reaction progress only.
It is also known that membranes prepared by microtechniques can be partially employed as functional elements in microreactors. However, these membranes are merely used for the separation of different phases within a reactor.
The reference WO 00/32512 describes Pd-based membranes for separating materials (e.g. H2 and CO in fuel cells) prepared by microtechniques, as well as the permeation of H2 through the membrane into a liquid phase on the other side of the membrane for the purpose of hydrogenation. Parallel coupling is described only in the context of enhancing the throughput, i.e., parallel coupling of identical reactors with identical catalysts.
Microstructured membranes for extraction as used in microreactors are described in W. E. Grotenhuis, R. J. Cameron, M. G. Butcher, P. M. Martin, R. S. Wegeng: Microchannel devices for efficient contacting of liquids in solvent extraction, 2nd International Conference on Microreaction Technology, Topical Conference Preprints, New Orleans/La., Mar. 1998, 329-334. Here, two different liquid phases can be brought into contact at these membranes to enable the exchange of materials without mixing of the two phases. Due to the different wetting behavior of the pores with respect to the liquid phases, each liquid phase remains at the side of the membrane it is intended to be.
In combinatorial chemistry, only micro- and nano-titration plates are known as “devices” for holding biological, biochemical or chemical samples. In addition, it is known that materials can be immobilized on a solid support and be screened at the same time, e.g., on large-scale sheets of specifically prepared filter paper (see C. E. Mallouk et al., Science 280 (1998), 1735ff). Nothing is known about such “devices” in the field of combinatorial materials research.